A highly compact 60-GHz lens-corrected conical horn antenna

We have developed a highly compact 60 GHz, lens-corrected conical horn for a Fast Ethernet wireless link. The horn has a diameter of 3 inches and a focal length of 1.5 inches. We use a two-step, hyperbolic, Rexolite lens to correct the aperture phase distortion caused by the 90-degree flare angle. The measured input return loss of the horn is 11 dB at 58.6 and 15 dB at 62.1 GHz, the link carrier frequencies. The measured gain is 27.6 dBi at 58.6 GHz and 28.6 dBi at 62.1 GHz. To our knowledge, these are the first reported results for a conical horn with such a wide flare angle in this frequency band.